This disclosure relates to poly(etherimide-siloxane) copolymers, and in particular to thermoplastic compositions comprising a combination of poly(etherimide-siloxane) copolymers and polyesters, methods of their manufacture, and articles containing the thermoplastic compositions.
Poly(etherimide-siloxane) copolymers have been used as coatings for electrical wires due to their flame resistant properties and high temperature stability. However, for some applications, greater impact strength, particularly in combination with low flexural modulus and high tensile elongation is desirable. Furthermore, to be useful in some high-heat, thin-walled wire coating applications, the wire coatings further need high tear strength. Accordingly, there remains a need in the art for improved poly(etherimide-siloxane) thermoplastic compositions having at the desired combination of physical properties, including low flammability, high temperature stability, and high impact strength. It would be particularly useful if the compositions further have low flexural modulus and high tensile elongation. For some applications, improved tear strength in combination with the foregoing properties would be especially useful.